The existing LED (Light Emitting Diode) street lamps are roughly divided into two kinds according to different light sources: one kind of street lamp adopts a single-chip small LED light source, namely, a street lamp which is composed of dozens of to hundreds of 1-3 W single-chip small LEDs and a light distribution lens array thereof; and the other kind of street lamp is composed of a chip on board (COB) module LED light source and a light distribution lens. The street lamp composed of a plurality of 1-3 W single-chip small LEDs and a light distribution lens array needs to have the power of 240 W and even higher under the requirement of large lighting range and high uniformity, e.g., when 5 lanes on a single side needs to be lighted, and then the street lamp needs to be composed of hundreds of LEDs and light distribution lenses thereof, so that the PCB (Printed Circuit Board) and the radiator are large and the lamp cap is also extremely huge. In addition, the combination of so many small LED light sources and the lenses thereof is generally high in manufacturing cost.
Moreover, the following external environmental factor should be considered: because the light distribution lens of the single 1-3 W single-chip small LED is substantially a plastic lens formed by injection molding and is generally made of PMMA (polymethyl methacrylate) or PC (polycarbonate), the lens may yellow and crack and the transparency declines sharply after 3-5 years of blowing, rain flushing, solarization, ultraviolet irradiation, heat expansion and cold contraction and dust adhesion. Electrostatic adsorption is the greatest threat to the plastic lens, and much dust may be adsorbed onto the surface of the lens after the lens is used for a period of time, the dust is solidified with water on the surface of the lens as lime and is difficult to clean, so that the optical efficiency of the lens is greatly influenced.
As to the so-called COB module LED light source, namely, chip On board module LED light source, a bare wafer is adhered to an interconnected substrate with conductive or non-conductive adhesive and then electrically connected with the substrate by lead bonding (the flip chip mode does not need lead bonding), thus realizing an LED wafer and substrate integrating technology.
FIG. 1 is a structural schematic diagram of the so-called COB module LED light source. The COB module LED light source is cheap, and one light source can generally integrate dozens of to hundreds of watts of chips. The single light source is much cheaper than dozens of to hundreds of 1-3 W single-chip small LEDs. In addition, a light source module only needs a glass light distribution lens and can meet the light distribution requirement of the street lamp, so the cost of the lens is reduced much. Generally, a several-hundred-watt street lamp can meet the road lighting requirement by adopting several COB module LED light sources.
The glass lens has other advantages: the transparency of the glass lens is relatively high, and the optical efficiency of the glass lens generally can reach over 95%; in addition, the glass lens is relatively good in corrosion and heat resistance, and will not be yellowed, scratched or influenced by static electricity after many years; and dust on the surface of the lens can be automatically flushed by rainwater.
Therefore, how to utilize the COB module LED light source to realize multi-lane lighting is the key of improving the lighting efficiency and reducing the production and use costs, and light distribution to the lighting lamp is the key of realizing multi-lane lighting with a single light source.
The disclosed methods and devices are directed to solve one or more problems set forth above and other problems.